Molecular Pathology of Lung Cancer

Angelo Paolo Dei Tos M.D. Departments of Pathology & Oncology

Treviso, ITALY

apdeitos@ulss.tv.it

WHO 2015

• Personalized medicine • Therapeutic decisions based on specific

histologic and genetic characteristics of tumor • Pathologists to classify NSCLC into specific

pathologic subtypes – adenocarcinoma versus squamous cell

carcinoma) • Eligibility for molecular testing and

consequent therapeutic strategies.

Molecular Testing in Lung Cancer

• Identification of molecular abnormalities in tumor specimens is required for therapy

• Limit the use of diagnostic immunohistochemical markers

• Pathology should determine the adequacy of specimens for molecular testing

Oncogene Addiction

• Tumor cells have many genetic abnormalities

• Driver mutations determines tumor cell survival

• Inactivation of upregulated oncogenic pathways

results in cancer cell death

MET

Driver Mutations in Lung Cancer (lung adenocarcinoma)

• EGFR, KRAS and ALK/ROS1/RET

• EGFR and/or ALK non smokers

• KRAS/BRAF smokers

EGFR-mutations in Adenocarcinoma

• 10-20% European area

• 50% East Asian area

• Randomized trials in patients with

advanced disease have shown

benefits for first-line treatment with

gefitinib, erlotinib and afatinib

EGFR-I mutations are not alike

Determination of EGFR mutations in NSCLC

• Adenocarcinoma

• Large cell carcinoma

• Mixed tumor with adenocarcinoma

• NSCLC NAS

Secondary Resistance to EGFR-I

• Additional somatic mutation in EGFR

(T790M)

• Amplification MET or ERBB2

• EGFR-I, EGFR antibodies and T790M

specific inhibitors under investigation

KRAS mutation adenocarcinoma

• 30% caucasian; 10% East Asian

population

• No response to EGFR-target agents

• Impact on overall survival remains

controversial

ALK rearrangements in NSCLC

ALK fusion protein in NSCLC

ALK/MET/ROS1 inhibitor crizotinib

ALK activating rearrangements

• 3-7% lung adenocarcinomas

• Good responder to ALK/MET/ROS1

inhibitor crizotinib

• Immunohistochemistry is a sensitive and

specific tool

• Vysis ALK Break-Apart FISH Probe Kit

• IHC = good surrogate biomarker

Crizotinib Resistant ALK + NSCLC

ROS and RET activating rearrangements

• 1% lung adenocarcinomas

• Good responder to ALK/MET/ROS1

inhibitor crizotinib

ERBB2 (HER2) mutations

• 1-5% lung adenocarcinomas

• Preclinical studies suggest that

ERBB2 inhibitors could be effective

BRAF mutation in NSCLC

• 2-10% lung adenocarcinomas

• The proportion of non-V600E

mutations is higher in lung cancer than

in other histotype

Squamous Cell Lung Carcinoma

Immunohistochemistry & ALK (Mino-Kenudson et al, CCR 2010)

• With the D5F3 clone high rates of sensitivity and specificity can be achieved (in experienced hands?)

• IHC remains a preferred technique for screening and diagnosis in

routine surgical pathology practice

• IHC-based screening can be used to identify lung adk harboring ALK

rearrangements

• *rabbit monoclonal anti-human CD246, Cell Signaling Technology

Our Approach

Diagnosis

adenocarcinoma

EGFR/KRAS molecular analysis + ALK/ROS IHC

• IHC 0 = negative

• IHC 1+/2 + = FISH

• IHC 3+ = positive

ALK

ALK

ROS

ROS

Int. J. Mol. Sci. 2015, 16, 14122-14142; doi:10.3390/ijms160614122

International Journal of Molecular Sciences

ISSN 1422-0067 www.mdpi.com/journal/ijms

Review

Circulating Cell-Free Tumour DNA in the Management of Cancer

Glenn Francis 1,2,3,* and Sandra Stein 4

1 Director Pathology, Genomics for Life, Herston 4006, Australia 2 School of Medicine, Griffith University, Gold Coast 4215, Australia 3 Australian Institute for Bioengineering and Nanotechnology, University of Queensland,

St Lucia 4067, Australia 4 Laboratory Director, Genomics for Life, Herston 4006, Australia;

E-Mail: srstein@genomicsforlife.com.au

* Author to whom correspondence should be addressed; E-Mail: gfrancis@genomicsforlife.com.au; Tel.: +61-1800-445-433.

Academic Editor: Camile S. Farah

Received: 22 February 2015 / Accepted: 26 May 2015 / Published: 19 June 2015

Abstract: With the development of new sensitive molecular techniques, circulating cell-free tumour DNA containing mutations can be identified in the plasma of cancer patients. The applications of this technology may result in significant changes to the care and management of cancer patients. Whilst, currently, these “liquid biopsies” are used to supplement the histological diagnosis of cancer and metastatic disease, in the future these assays may replace the need for invasive procedures. Applications include the monitoring of tumour burden, the monitoring of minimal residual disease, monitoring of tumour heterogeneity, monitoring of molecular resistance and early diagnosis of tumours and metastatic disease.

Keywords: cell-free DNA; cell-free tumour DNA; non-small cell lung cancer; melanoma; colorectal carcinoma; minimal residual disease; liquid biopsy

1. Introduction

A biomarker is a chemical or biological compound that can be used to diagnose or monitor disease. For cancer, the aims of a sensitive biomarker are to enable early detection of cancer, monitoring of disease progression and response to treatment. Biomarkers can be broadly grouped into predictive

OPEN ACCESS

Conclusions

• Multiprofessional approch

• Morphology still very important

• Molecular tools predict response and

resistance to targeted therapies

• IHC good surrogate for molecular

analysis of ALK/ROS1

• NGS approches

apdeitos@ulss.tv.it